1、 1 5G Americas White Paper Network Slicing for 5G and Beyond TABLE OF CONTENTS 1.0 Introduction . 2 2.0 Role of Network Slicing in 5G . 3 2.1 5G Requirements on Network Slicing . 3 2.2 How Network slicing can fulfilL these requirements 4 2.3 Benefits to operators . 4 3.0 Network slicing system archi
2、tecture (E2E network slicing) . 5 4.0 Network slicing in CN 8 5.0 Network slicing in THE RAN . 10 6.0 Operational aspects of network slicing . 13 6.1 Network Slices Management Framework 13 6.2 Network slicing management and ETSI NFV MANO 16 6.3 Network slice management . 18 6.3.1 Network slice life
3、cycle management 18 6.3.2 Configuration Management . 20 6.3.3 Performance management 20 7.0 Opportunities introduced by network slicing . 23 7.1 Evolution of Slicing Technology 23 7.2 Services to Virtual Operators 23 7.3 Further benefits of network slicing . 23 8.0 Conclusions . 25 Appendix A: Summa
4、ry of Existing Works . 26 Appendix B: Network slicing in 4G 29 Appendix C: Acronyms and Definitions . 31 Acknowledgements . 34 2 5G Americas White Paper Network Slicing for 5G and Beyond 1.0 INTRODUCTION 5G cellular systems are expected to enable a major digital transformation that will provide peop
5、le, businesses and governments with unprecedented capabilities to share information. The industry consensus is that 5G should be known not only for its cutting-edge radio access technologies, but also for the way it integrates cross-domain networks so operators can provide networks on a need-for-ser
6、vice basis. 5G will enable new verticals, new services and new business models that arent possible or practical with 4G and other legacy mobile technologies. Examples includes wearables for advanced telemedicine applications, virtual/augmented reality, UHD video and machine-to-machine (M2M) applicat
7、ions that require single-digit-millisecond latencies such as driverless cars. 5G technologies aim to provide an end-to-end infrastructure capable of delivering a consistent user quality of experience in a heterogeneous environment across a wide variety of use cases. To achieve this goal, 5G must be
8、able to support very high bit rates, high vehicular speeds, low latencies and high device densities. One example is Internet of Things (IoT) applications, where there may be thousands of 5G devices within a single acre, all requiring single-digit-millisecond latencies and other capabilities that leg
9、acy mobile technologies cant support well or at all. Designing a network that can simultaneously support both a wide variety of use cases and demanding performance requirements, all with a single set of standard network functions, would be extremely complex and prohibitively expensive. The alternati
10、ve “network slicing,” which is considered to be key for meeting 5Gs diverse requirements, including future-proof scalability and flexibility. The network slicing concept enables the network elements and functions to be easily configured and reused in each network slice to meet a specific requirement
11、. The implementation of network slicing is conceived to be an end-to-end feature that includes the core network and the RAN. Each slice can have its own network architecture, engineering mechanism and network provisioning. Existing cellular network architectures are relatively monolithic, with a tra
12、nsport network that facilitates mobile traffic to end devices. They are not flexible enough to support wider range of performance and scalability requirements. Network slicing would allow 5G networks to be sliced logically into multiple virtual networks. Each slice can be optimized to serve a specif
13、ic vertical application to efficiently support network services, thus providing high degree of flexibility in enabling several use cases to be active concurrently. This is already a well understood methodology in the wireless industry in some limited environments, such as software-defined core netwo
14、rks. Network slicing leverages the latest innovations in cloud mobile access and core. Combining cloud technologies with the capabilities of software defined networking (SDN) and network function virtualization (NFV) provides the necessary tools to enable network slicing. Virtualization technologies
15、 provide a key foundation for network slicing by enabling use of both physical and virtual resources to create the service they are designed for. It is envisioned that this trend will continue, where virtualization technologies will be applied across RAN and portable services and across portable dev
16、ices to wearable devices. Network slicing implementation is end-to-end from the core through the RAN. In the core, NFV and SDN virtualize the network elements and functions in each slice to meet its own requirement. In the RAN, slicing can be built on physical radio resources (e.g., transmission poi
17、nt, spectrum, time) or on logical resources abstracted from physical radio resources. 3 5G Americas White Paper Network Slicing for 5G and Beyond The commercial introduction of NFV/SDN (Network Function Virtualization/Software Defined Network) based 4G EPC networks is now occurring and is expected t
18、o grow tremendously over the next several years. This will allow network slicing to enable much more flexible instantiations of networks that can be designed to meet the specific needs of the applications, services and operator business models. Both NGMN1 and 3GPP2 have been developing the definitio
19、n and use cases for network slicing so that the SDOs (Standards Development Organizations) can provide detailed studies to understand the features and functionalities that will be required for network slicing beyond what is already defined in 3GPP Rel-13 and ETSI NFV.3 This white paper intends to de
20、scribe the concept of network slicing, explore an end-to-end 5G system framework to build customized network slices, and discuss the application of network slicing to air-interface technologies. This paper initiates the discussion and development on the long-range technology roadmap and solutions fo
21、r E2E network slicing in 5G and beyond. Furthermore, the white paper is organized as follows: section 2 discusses the role of network slicing, the basic 5G requirements for network slicing and the benefits to the operators. Section 3 provides a description of an end-to-end network slicing system arc
22、hitecture. The network slicing framework in CN and RAN are detailed in Sections 4 Stage 1”, Release 14. 3 ETSI GS NFV 002 v1.2.1 (2014-12). 4 Ibid. 4 5G Americas White Paper Network Slicing for 5G and Beyond The 3GPP system shall have the capability to provide a level of isolation between network sl
23、ices to confines a cyber-attack to a single network slice The operator shall be able to authorize third parties to create, manage a network slice configuration (e.g., scale slices) via suitable APIs, within the limits set by the network operator The 3GPP system shall support network slice elasticity
24、 in terms of capacity with no impact on the services of this slice or other slices The 3GPP system shall be able to change the slices with minimal impact on the ongoing subscribers services served by other slices: specifically, of new network slice addition, removal of existing network slice or upda
25、te of network slice functions or configuration The 3GPP System shall be able to support end-to-end resource management for a network slice What these requirements describe is an efficient, powerful, flexible system that operators can tailor to their specific needs. Using building block functions tha
26、t can be assembled in a variety of ways, operators can assemble the functionality needed to efficiently support different needs, such as IoT devices that never move, smartphones and corporate devices requiring very secure VPN services. 2.2 HOW NETWORK SLICING CAN FULFILL THESE REQUIREMENTS Network s
27、licing, in its simplest description, is the ability to tailor a set of functions to optimize use of the network for each mobile device. All of the functionality needed, but only the functionality needed, is assembled in a way that optimizes that devices ability to find the correct network, access th
28、e network efficiently and securely, and be attached to the core network with the set of functionality needed by that device. A device that is simple and requires only access to a single slicefor example, a water meter readercan find a radio interface that is tailored to very small, infrequent messag
29、es. That RAN attaches the device to a simple, efficient authentication process that results in the device being connected to a single core network slice that handles just water meter reader devices. As such, the connected functionality provides all that the device needs to accomplish its work, witho
30、ut the overhead of unneeded functions and features. A device that is more complex and provides rich functionality, such as a smartphone, can find the radio interfaces that it needs, as well. The device can be authenticated and attached to a diverse set of network slices that are each tailored to a s
31、pecific purpose: streaming video, voice calls, internet browsing, chatting and so on. Such devices may need to carry on high-quality voice and video calls, while at the same time continuing background browsing and upload/download functions. The independence of network slices indicated in the 3GPP re
32、quirements ensures that the high-quality video call that it will not be interrupted nor impacted by other background functions. Such services as video calling can be established with high security, while the security applied to other activities may use completely different methods. But at the same t
33、ime that these network slicing features are supporting very specific needs of devices and their users, they are also providing the ability to the network operators to deploy only the specific functions needed to satisfy their customers needs. This ability to focus on what is needed reduces investmen
34、t in unnecessary features, saving operators money and making them more competitive. 2.3 BENEFITS TO OPERATORS An immediately obvious benefit to operators is the ability to deploy only the functions needed to support particular customers and particular market segments. Additional functionality not ne
35、eded for the particular customer or market segment need not be deployed. This results directly in savings compared to being 5 5G Americas White Paper Network Slicing for 5G and Beyond required to deploy full functionality to support devices that will use only a part of that functionality. And a deri
36、vative benefit is the ability to deploy 5G systems more quickly because fewer functions need to be deployed, enabling faster time-to-market. Sections 7 and 8 provide an in-depth discussion of these and other operator benefits. 3.0 NETWORK SLICING SYSTEM ARCHITECTURE (E2E NETWORK SLICING) Figure 1 il
37、lustrates the system architecture used in network slicing. NF 1 NF 2NF 1 NF 3NF 1 NF 2NF 1NF 1 NF 2 NF 3NF 1 NF 2R A N S l i c e # 4C N S l i c e # 1C N S l i c e # 2C N S l i c e # 3C N S l i c e # 4C N S l i c e # 5C N S l i c e # 6NF 3S l i c e p a i r i n g fu n c t i o n b e t w een R A N /f i
38、x ed a c c es s a n d C NR A N S l i c e # 3R A N S l i c e # 2R A N S l i c e # 1F i x ed A c c es s S l i c e # 1F i x ed A c c es sS l i c e # 2Figure 1. Network Slicing Architecture. The network slicing architecture contains access slices (both radio access and fixed access), core network (CN) s
39、lices and the selection function that connects these slices into a complete network slice comprised of both the access network and the CN. The selection function routes communications to an appropriate CN slice that is tailored to provide specific services. The criteria of defining the access slices
40、 and CN slices include the need to meet different service/applications requirements and to meet different communication requirements. Each CN slice is built from a set of network functions (NFs). An important factor in slicing is that some NFs can be used across multiple slices, while other NFs are
41、tailored to a specific slice. The mapping among devices, access slices and CN slices can be 1:1:1 or 1:M:N, as Figure 2 illustrates. For example, a device could use multiple access slices, and an access slice could connect to multiple CN slices. 6 5G Americas White Paper Network Slicing for 5G and B
42、eyond NF 1 NF 2NF 1 NF 3NF 1 NF 2NF 1NF 1 NF 2 NF 3NF 1 NF 2R A N S l i c e # 4C N S l i c e # 1C N S l i c e # 2C N S l i c e # 3C N S l i c e # 4C N S l i c e # 5C N S l i c e # 6NF 3S l i c e p a i ri n g f u n c t i o n b e t w een R A N /f i x ed a c c es s a n d C NR A N S l i c e # 3R A N S l
43、 i c e # 2R A N S l i c e # 1F i x ed A c c es s S l i c e # 1F i x ed A c c es sS l i c e # 2D e v i c e AD e v i c e BD e v i c e CD e v i c e DD e v i c e EFigure 2. UE Connection with the Network Slices. The pairing between access slices and CN slices can be static or a semi-dynamic configuratio
44、n to achieve the required network function and communication needs. A network slice would last throughout the intended service lifetime and would provide full network function support to the devices connected with the network slice. Examples of network slices include: A slice serving a utility compa
45、ny A slice serving remote control for a factory A slice serving a virtual operator A slice optimized for streaming video 7 5G Americas White Paper Network Slicing for 5G and Beyond Figure 3 illustrates some examples: V id e o St r e a m in g Su p p o r t M M S Su p p o r t V o ic e C a ll s a n d Fe
46、 a t u r e s Se r v ic e C o n t in u i t y C h a r g in g Su p p o r t Da t a P a t h O p t im iz a t io n . . . Sm a ll D a t a O p t im iz a t io n B a t t e r y C o n s e r v a t io n C h a r g in g Su p p o r t . . . M V N O O p e r a t o r F e a t u r e S e t M B B S u p p o r t O p e r a t o
47、r S p e c if ic C h a r g in g . . .R A N S l i c e # 4C N M B B S l i c eC N I o T S l i c eC N M V N O S l i c eR A N S l i c e # 3R A N S l i c e # 2R A N S l i c e # 1F i x ed A c c es s S l i c e # 1F i x ed A c c es sS l i c e # 2I o TDe v ic eS m a r tP h o n eM V N OUEFigure 3. Network Slice
48、 Examples. As Figure 3 shows, some slices can share an access slice, as is shown in the example for the “Smart Phone” and “MVNO UE” devices. For instance, slices serving different utility companies can all be connected to the access slice tailored for supporting massive machine type communication (m
49、MTC), while the slice optimized for streaming video can share the access slice for mobile broadband (MBB). Some slices would have a dedicated access slice and CN slice. For example, a slice for factory remote control may need to have dedicated access and CN functions to provide guaranteed performance such as latency and reliability. A fixed broadband access slice could have a dedicated CN slice tailored for the fixed access. Later sections of this paper discuss enabling technologies in access and core network slices. Slicing at th
